- MCMAHON TRANSPORT LTD- 16522930 - Incorporated on 17 June 2025 
- MCMAHON SERVICES LTD- 14402338 - Incorporated on 6 October 2022 
- ADAM MCMAHON LIMITED- 14437246 - Incorporated on 24 October 2022 
- MCMAHON ASSOCIATES LTD.- 02447479 - Incorporated on 29 November 1989 
- MCMAHON DEVELOPMENTS LIMITEDDissolved- 05285538 - Dissolved on 20 April 2010 
- JOANNE MCMAHON LIMITEDDisolved- 06686346 - Dissolved on 23 July 2024 
- NIALL MCMAHON LIMITED- 03905180 - Incorporated on 12 January 2000 
- MCMAHON MEDIA LIMITEDDissolved- 07627135 - Dissolved on 24 December 2013 
- JOHN MCMAHON LIMITEDActive - Proposal to Strike off- 07734472 - Incorporated on 9 August 2011 
- TONY MCMAHON LIMITEDActive - Proposal to Strike off- 09677422 - Incorporated on 8 July 2015 
- MCMAHON SOLUTIONS LTD- SC448952 - Incorporated on 30 April 2013 
- LANE MCMAHON LIMITED- 07415590 - Incorporated on 21 October 2010 
- BRIAN MCMAHON LIMITEDDissolved- 09192582 - Dissolved on 15 October 2019 
- MCMAHON CONSTRUCTION LTDDisolved- 12294156 - Dissolved on 26 July 2022 
- LOUIS MCMAHON LIMITEDDisolved- 10961364 - Dissolved on 15 February 2022 
- MCMAHON MCKAY LIMITED- NI635772 - Incorporated on 13 January 2016 
- MCMAHON MECHANICAL LIMITEDActive - Proposal to Strike off- 10293498 - Incorporated on 25 July 2016 
- TONY MCMAHON LIMITEDDisolved- 12485171 - Dissolved on 30 August 2022 
- MCMAHON CONTRACTORS LTDDisolved- SC682355 - Dissolved on 22 August 2023 
- MCMAHON MARKETING LIMITEDDisolved- SC724504 - Dissolved on 23 May 2023